Unable to write files on sdcard android

Question

I have an app which saves backup files on SD-Card. It works fine on HTC Nexus One, and other android phones, but with some phones it doesn\'t work (reading or writing).

Answer 1

I have Sony Xperia tipo dual and this:

FILE* pFile = fopen("/mnt/sdcard/mydata.dat","w+");

and this:

FILE* pFile = fopen("/sdcard/mydata.dat","w+");

Both work ok. (I did it in Native)